JP5841139B2 - Method, system, and apparatus for calibration of a position offset between an end effector and a position sensor - Google Patents

Description

  This application is a US Provisional Patent Application No. 61 / 357,227 (filed June 22, 2010, entitled “METHODS, SYSTEMS, AND APPARATUS FOR CALIBRATION OF A POSITIONAL OFFSET BETWEEN AN END EFFECTOR AND A POSITION SENSOR”). (Attorney Docket No. 2010P07651US)), which is hereby incorporated by reference in its entirety for all purposes.

  The present invention relates generally to systems, apparatus, and methods adapted to calibrate robot components.

  In medical testing and processing, the use of robotics may minimize exposure to or contact with bodily fluid samples (also known as “test objects”) and / or improve productivity. . For example, in some automated test and processing systems (eg, clinical analyzers and centrifuges), sample containers (eg, test tubes, sample cups, vials, etc.) sample racks (sometimes referred to as “cassettes”) And from there to the test or processing system. Similarly, the sample rack itself can be transported from one location to another in conjunction with a test or processing system.

  Such transfer can be accomplished by using an automated mechanism, which includes a robotic component having a movable end effector (eg, movable) that may have two or more gripper fingers coupled thereto. Robot arm or gantry mechanism). The end effector can be moved in two or more (eg, X, Y, and Z) coordinate directions. In this way, a sample container (which contains a sample piece to be tested or processed) or a sample rack is gripped by an end effector and then moved from one location to another in conjunction with the testing or processing system. be able to.

  Inaccurate positioning of the end effector may cause a collision between the end effector and the sample container and / or between the sample container being moved and the instrument or sample rack. If the sample rack is being moved, the incorrect positioning of the end effector may cause a collision between the sample rack and the test or processing system. In addition, inaccurate calibration may contribute to fluctuations in the pick and place operation of the sample container and / or sample rack, which may contribute to unwanted leakage of the specimen. Accordingly, systems, apparatus, and methods that can improve the accuracy of positioning of sample containers and sample racks transported to and from the test or processing system are desired.

  In a first aspect, an improved system is provided. The system includes a robot offset calibration system including a robot component having an end effector and a position sensor coupled thereto, a teaching object having a first geometric feature, and an offset adapted to be engaged by the end effector. A tool, an offset tool including a first docking function, a second docking function adapted to be engaged by the first docking function, and a second adapted to be detected by the position sensor And offset objects having geometric features.

  In a method aspect, an improved method of calibrating sample container transfer is provided. The method includes providing a robot component having an end effector and a position sensor coupled thereto, providing a teaching object having a first geometric feature in a work range reachable by the end effector, Providing an offset object that is reachable and includes a second geometric feature, providing an offset tool, detecting a first geometric feature to be taught by a position sensor, and an offset tool Engaging the end effector, moving the offset tool to the offset target, docking the offset tool with the offset target, and detecting a second geometric feature of the offset target with the position sensor. Including.

  In an apparatus aspect, a calibration aid is provided. The apparatus includes a base, a nesting tool mounted on the base, a teaching object having a first geometric feature adapted to be detected by a position sensor, a first object mounted on the base, An offset tool having one docking function, a second docking function installed on the base and adapted to be engaged by the first docking function of the offset tool, and adapted to be detected by a position sensor And an offset object having a second geometric feature.

  In another apparatus aspect, a calibration aid assembly is provided. The assembly includes a tray and a nesting tool coupled to the tray, the nesting tool being mounted on the base and having a first geometric feature adapted to be sensed by a position sensor. A teaching object having, an offset tool mounted on the base and having a first docking function, and a second docking mounted on the base and adapted to be engaged by the first docking function of the offset tool An offset object having a function and a second geometric feature adapted to be detected by the position sensor.

  Still other aspects, features and advantages of the present invention will become apparent from the following detailed description, by way of illustration of numerous exemplary embodiments and implementations, including the best mode contemplated for carrying out the invention. Can be readily apparent. The invention may be capable of other and different embodiments, and its several details can be modified in various respects, all without departing from the spirit and scope of the invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. The drawings are not necessarily drawn to scale. The present invention is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

FIG. 3 is a partial cross-sectional side view illustrating an example of a calibration aid assembly of an embodiment of the present invention. 2 is a graphical depiction of a side view illustrating the movement of a position sensor relative to a teaching object in an embodiment of the present invention. 2 is a graphical depiction of a side view illustrating the movement of a position sensor relative to a teaching object in an embodiment of the present invention. 2 is a graphical depiction of a top view illustrating movement and positioning of a position sensor in an XY coordinate relative to a teaching object, in accordance with an embodiment of the present invention. It is a side view of the end effector which grasps and picks the offset tool of the embodiment of the present invention. It is a side view of the end effector which docks an offset tool with a movable offset object of an embodiment of the present invention. It is a side view of the position sensor which measures the coordinate of the place of offset object of the embodiment of the present invention. FIG. 7 is a partial cross-sectional side view illustrating an alternative docking function for an offset tool and offset object, according to an embodiment of the present invention. FIG. 7 is a partial cross-sectional side view illustrating an alternative docking function for an offset tool and offset object, according to an embodiment of the present invention. FIG. 7 is a partial cross-sectional side view illustrating an alternative docking function for an offset tool and offset object, according to an embodiment of the invention. 1 is a perspective view illustrating a test system including an example calibration aid assembly having a nesting tool coupled to a tray of an embodiment of the present invention. FIG. FIG. 2B is a perspective view illustrating the test system of FIG. 2A with the example calibration aid assembly with various centrifuge components removed for clarity of embodiments of the present invention. 2B is a perspective view illustrating the test system of FIG. 2A including an example robotic device positioned on a nesting tool of an embodiment of the present invention. FIG. 2 is a partial perspective view illustrating an example calibration aid assembly having a nesting tool coupled to a tray, in accordance with an embodiment of the present invention. FIG. It is a perspective view of the example of the nesting tool of embodiment of this invention. It is a perspective view of the example of the nesting tool of embodiment of this invention. It is a perspective view of the example of the nesting tool of embodiment of this invention. It is a fragmentary perspective view of the example of the calibration block installed in the cradle of the centrifuge of embodiment of this invention. FIG. 5B is a perspective view of the teaching object of the example of FIG. 5A according to an embodiment of the present invention. FIG. 5B is a perspective view of the teaching object of the example of FIG. 5A according to an embodiment of the present invention. FIG. 5B is a top view of the subject of the example of FIG. 5A according to an embodiment of the present invention. 1 is a perspective view of an example of a calibration nesting tool installed at multiple locations according to an embodiment of the present invention. FIG. 4 is a flowchart illustrating a method of an embodiment of the present invention.

  In robotic devices, such as those used to achieve robot pick and place operations for the reasons described above, it is desirable to achieve accuracy in placement of robot end effectors. As used herein, an “end effector” is any member coupled to a robot that is used for robot operations such as pick and place operations. In some systems, position sensors (eg, ranging sensor sensors) may be used with the robot end effector of the robot system. In such robotic systems, a positional accuracy of a few thousandths of an inch or less may be desirable. However, in many cases, tolerance accumulation from many connected system components can reach thousands, or tens of thousands or hundreds of thousands of inches. Therefore, a means for properly calculating the actual position offset (eg, in x, y, and z space) between the robot end effector and a position sensor in such a robot system is desired. In addition, once calibrated with an appropriate position offset, it may be desirable to precisely place other system components that are reachable by the robotic device.

  In view of the foregoing problems, the present invention provides a calibration method, calibration assistance system, and calibration assistance device for easily calculating the actual (real) position offset between an end effector and a position sensor in a robot system. To do. In a first aspect, a calibration method includes providing a teaching object, an offset tool, and an offset object, which are collectively used to obtain a position offset between an end effector and a position sensor of a robot system. Used. According to this method, the position sensor can detect (measure) the first geometric feature of the teaching target and obtain first position information (for example, X, Y, and Z). The offset tool is engaged (eg, gripped) by the end effector in a known orientation relative to the end effector and moved to the position to be offset. Thereafter, the offset tool is docked to the offset object. Docking may include engaging the docking function of the offset tool with the offset object. For example, one or more surfaces of the offset tool may be docked with one or more surfaces to be offset. One or more docking surfaces may be inclined with respect to a vertical axis (for example, the Z axis). If it is possible that some tolerance accumulation exists in the robot system, the docking motion will cause the offset object to shift or move slightly in one or more directions (eg, causing motion in xy space). There is a case. In any case, the docking operation positions the centerline to be offset, thereby matching the centerline of the end effector (eg, in xy space). A second geometric feature of the offset object having a known relationship with the center line of the offset object (preferably coincident with it) and another surface (eg, the upper surface) can then be measured by the position sensor. From the measured position coordinate information collected from the teaching object and the offset object, a position offset between the machine position of the end effector and the actual position detected by the position sensor can be calculated in one or more coordinate directions. This calculates the actual offset in the X, Y or Z direction, X and Y only, X and Z only, X and Y only, and preferably all 3 directions (eg X, Y and Z). May be included.

  In another aspect, a calibration aid is provided. The calibration aid is referred to herein as a “nesting tool” and includes a base and a teaching object having a first geometric feature mounted on the base and adapted to be detected by a position sensor; An offset tool mounted on the base and having a first docking function, and a second docking function slidably mounted on the base and adapted to be engaged by the first docking function of the offset tool And an offset object further comprising a second geometric feature adapted to be detected by the position sensor. In another aspect, the calibration aid assembly may include a tray on which the nesting tool described above is coupled. However, it will be apparent that the nesting tool may be located anywhere within the reach of the robotic device. In addition, one or more nesting tools may be used.

  In another aspect, a robot offset calibration system is provided. The offset calibration system is adapted to be engaged by the end effector with a robot component having an end effector and a position sensor coupled thereto, a teaching object having a first geometric feature, A second geometric feature adapted to be detected by a position sensor having an offset tool including a docking function and a second docking function adapted to be engaged by the first docking function The offset object further includes

  These and other aspects and features of the present invention are described herein with reference to FIGS.

  In the first embodiment of the present invention, a robot offset calibration system 100 is described, as best shown in FIG. 1A. The robot offset calibration system 100 is useful to assist in the calibration of any robotic system, such as those used in automated clinical analyzers, centrifuges, or other processing systems (eg, body fluid analyte processing systems). The robot offset calibration system 100 includes a robotic device that includes a robot component 102 having an end effector 104 and a position sensor 106 each coupled thereto. The position sensor 106 may be coupled directly to a part of the end effector 104 or to a part of the robot component (eg, to a robot arm, boom, or beam), but between the end effector 104 and the position sensor 106. The place is fixed. Similarly, the Z dimension between the lower end ends of the gripper fingers 104A, 104B of the end effector 104 and any preset range of the position sensor 106 is also fixed.

  The controller 108 is in one or more coordinate directions and preferably in two or more or three directions with respect to the robot component 102, the attached end effector 104 and the position sensor 106, but preferably in X, Y, and Z dimensions. The space can be commanded to move, where Y is in and out of the page of FIG. 1A. Any suitable robot component 102 may be used, such as a mobile robot arm, boom, or beam having an end effector 104 coupled thereto. In some embodiments, the robotic component 102 may include one or more shoulders, elbows, or wrist members for achieving three dimensional movement of the end effector 104.

  In other embodiments, for example, in the processing system 200 of FIGS. 2A-2C, the robotic component 102 may be mounted on the frame 201 and may have a movable gantry mechanism with an end effector 104 mounted on the boom 203. . The boom 203 may be movable (eg, in the Z direction) on a suitable track or guide. Further, the boom 203 (and the end effector 104) may be movable in one or more additional directions (eg, X and / or Y directions) along the track or guide. In the illustrated embodiment, movement of the end effector 104 is provided in the X, Y, and Z coordinate directions. The means for moving the robot component 102 may include any suitable conventional motion generation mechanism, such as a stepper motor, servo motor, pneumatic or hydraulic motor, electric motor, and the like. In addition, a drive system including a chain, guide, pulley and belt device, gear or worm drive or other conventional drive component may be utilized to cause movement of the robot component 102 and the combined end effector 104. Other types of robotic devices may be used.

  The illustrated processing system 200 is an automatic centrifuge system adapted to separate various components of a test object provided therein. In particular, the centrifuge 205 may be a Hetrich centrifuge available from Hetrich Centrifuges (Beverly, Mass.), Which is the yoke 207 of the centrifuge 205 (see FIGS. 2A-2C and FIG. 5A). Is adapted to receive a sample rack (also referred to as a “sample cassette”) in a bucket 206 pivotally mounted to. For clarity, only the bucket 206 and yoke 207 of the centrifuge 205 are shown in FIGS. 2B and 5A. The tray 130 of the processing system 200 may be coupled to a weighing mechanism 209 (eg, a weigh scale) that is adapted to measure the weight of each cassette or the like mounted on the tray 130. Further, the nesting tool 128 is illustrated as being installed on the tray 130. Other processing components may be attached to the frame 201 but are not shown for clarity. Although the illustrated example is directed to a processing system 200 that is an automatic centrifuge system, the methods, calibration aids, systems, and nesting tools of the present invention are applicable to other types of automatic processing systems, and even automatic It should be understood that it has utility for test systems.

  Referring again to FIG. 1A, the opposing gripper fingers 104A, 104B (only one finger 104A is shown in FIG. 2C) can be placed on any XY plane by a suitable end effector drive, such as a servomotor. It can be driven to open and close along a suitable direction (eg, X or Y direction). For example, a pneumatic or hydraulic servomotor or electric motor may be used. Any suitable mechanism for causing the gripping action of the fingers 104A, 104B may be used. Further, although two fingers are shown, the present invention is equally applicable to end effectors having two or more fingers or grippers.

  Referring back to FIG. 1A, the robot offset calibration system 100 includes a teaching object 110, an offset tool 114, and an offset object 118. The teaching object 110, the offset tool 114, and the offset object 118 can be mounted on a common base 126 and can create the components of the nesting tool 128. The nesting tool 128 can be placed anywhere on the processing system 200 within the reach of the robot component 102 (FIGS. 2A-2C) and the end effector 104 and position sensor 106 of the robot offset calibration system 100. It can be used to assist in the calculation (calibration) of the position offset between.

  In the illustrated embodiment, the teaching object 110 is a generally cylindrical column extending upwardly from the base 126 of the nesting tool 128 and includes a first geometric feature 112 formed thereon. The teaching object 110 may be fastened to the base 126 by any suitable means, such as screws, bolts, press fit, adhesive, brazing, welding, or other suitable fastening system. The first geometric feature 112 may be a disc, rectangle, square, or any other geometric feature and is at least in one direction by the position sensor 106, but preferably at least X And ends that can be arranged in the Y direction, and preferably in the X, Y, and Z directions. The first geometric feature 112 may include a first plane 112A located substantially in the XY plane, and may include two or more stepped end faces on opposite sides thereof. The first plane 112A is adapted to be detected vertically (Z direction) by the position sensor 106. The first plane 112A is vertically offset from the second plane 112B of the teaching object 110 located at a different vertical level (eg, vertically downward) than the first plane 112A so that the entire horizontal dimension is It may be different (eg smaller), which provides a stepped surface in the vertical direction. The measured surfaces 112A, 112B and edges need to be precision machined so that their location on the nesting tool 128 is precisely known.

  The offset tool 114 may be adapted to be engaged by the end effector 104 (eg, by gripper fingers 104A, 104B). The offset tool 114 may include a first docking function 116 that is adapted to be engaged with the second docking function 120 of the offset object 118. In some embodiments, the first docking feature 116 and the second docking feature 120 may include an engagement surface (eg, one or more inclined surfaces) that will be better described below. The offset tool 114 may include a pilot 114A that extends vertically in the Z direction from the location of the first docking feature 116 and shelf 114B, which may extend laterally in the XY plane, for example. The shelf 114B is adapted to be contacted by the end effector 104 when the end effector 104 grips the offset tool 114. In particular, when the offset tool 114 is gripped, the fingers 104A, 104B are placed in vertical contact with the top surface of the shelf 114B (see FIG. 1E). In addition, the offset tool 114 further includes a positioning function 114C for roughly positioning the offset tool 114 relative to the base 126, eg, a centering pilot on the lower surface. In some embodiments, the offset tool 114 is placed on the compliant member 132 of the nesting tool 128. This allows the offset tool 114 to be positioned relative to the base 126 so that the offset tool 114 can be positioned and gripped by the end effector 104. Other types of centering functions may be used.

  The compliant member 132 may be any suitable spring member, such as a spiral or coil spring, a wave spring, a leaf spring, a spiral spring, a disc spring, an air spring, and the like. The compliant member 132 may be suitably installed so that movement relative to the base 126 is limited. By providing the compliant member 132, it is possible to easily grasp the offset tool 114, and at the same time, it is possible to minimize a load spike when the ends of the fingers 104A and 104B contact the shelf 114B.

  An offset object 118 can also be mounted on the base 126. The offset object 118 may include a second geometric feature 122 that is adapted and / or intended to be detected by the position sensor 106. In some embodiments, the first and second geometric features 112, 122 may include substantially similar functions. For example, they may both include substantially the same diameter discs formed or provided thereon. Further, the second geometric feature 122 may include first and second offset surfaces (eg, planes) 122A, 122B, as described above for the teaching object 110.

  The docking feature 116, 120 may be any suitable geometric feature, including an engagement surface, whereby an offset object 118 in the X, Y, or X and Y directions relative to the end effector 104. Centering becomes possible. In the illustrated embodiment, the first docking feature 116 includes a conical (tilted) surface formed on the underside of the offset tool 114. However, the inclined surface may be a complex inclined surface (see FIG. 4C). For example, the first docking feature 116 may include a plurality of intersecting conical surfaces or arcuate (curved) surfaces that are oriented at different cone angles. The second docking feature 120 of the offset object 118 can also include an inclined surface, which is adapted to join the engagement surface of the first docking feature 116. For example, the second docking function 120 can be formed on top of the offset object 118.

  In the embodiment illustrated in FIGS. 1A and 1F, the second docking feature 120 includes a curved surface (eg, a spherical surface) and is tilted precisely centered with respect to the second geometric feature 122 (eg, a disc). Including face. The portion of the spherical surface that contacts the first docking function 116 is inclined with respect to the vertical axis (Z axis). However, a conical surface or other inclined or curved surface shape may be used as the second docking function 120. Optionally, as shown in FIGS. 1H-1J, the docking features 116, 120 and offset object 118 of the offset tool 114 of FIGS. 1A and 1F may be inverted, respectively. For example, as shown in FIGS. 1H-1J, an extension (convex) function 116A may be provided on the offset tool 114A, and a receiving (concave) function 120A may be provided on the offset object 118A. Any combination of convex and concave members to be joined may be used as the first and second docking functions 116A, 120A. In some embodiments, only one of the docking features may include a ramp (see FIG. 1J), but preferably both include ramps. Both docking functions 116A, 120A may include a conical surface as shown in FIG. 1I, but matching such functions may later cause shift errors. Therefore, such a matched function should be used only if a relatively low level of accuracy may be tolerated. Any suitable geometry that allows centering of the offset object 118 in the X and / or Y coordinate directions may be used. However, configurations including docking features 116A, 120A (or 116, 120 shown in FIG. 1H) that include a spherical surface on one member and a conical surface on the other, as shown in FIG. 1H, provide excellent location accuracy. .

  The offset object 118 may include a smooth, flat lower surface 118C that engages a smooth plane of the base 126. If the end effector 104 is placed at a predetermined second nominal location of the offset object 118 in the X, Y space, the docking operation as shown in FIG. Match (move) the center line 104C of the effector 104.

  In the embodiment illustrated in FIGS. 1A-1F, the position sensor 106 is a laser ranging sensor, which is adapted to emit a plurality of intersecting laser beams 106A toward the target (for clarity, 1 Only one beam is shown). In the illustrated embodiment, the position sensor 106 is a function of the position of the object to be grasped (eg, cassette, specimen container or vial, test tube, cuvette, tool, etc.) or where the object is located ( For example, it may be operable to detect the position of holes, slots, pilots, pins, cutting edges, etc. The position sensor 106 may be any suitable position sensor adapted to calculate a position in one or more coordinate directions, but is preferably a laser ranging sensor. A class 2 red laser ranging sensor available from Banner Engineering (Minneapolis, Minnesota) has been found effective. Other types of laser sensors may be used depending on the number of coordinate dimensions desired to be measured. Other types of position sensors (eg contact type) may be used as well.

  In the present calibration aid system and method, the position sensor 106 is adapted to sense the first geometric feature 112. For example, as shown in FIG. 1A, the position sensor 106 can be moved from a nominal rest position of (X0, Y0, Z0) to a known nominal position on the teaching object 110. The teaching object 110 may be provided at a nominally known position in the X, Y, Z space as part of the calibration process so that the controller 108 can be positioned at that nominal location in the space. The movement of the sensor 106 can be commanded. For example, the teaching object 110 may be provided at any known position within the reachable range (working range) of the robot component 102. In some embodiments, the nesting tool 128 may be handled by the operator in a predefined location and direction in X, Y, Z space manually by the operator or by gripping the nesting tool 128 with the end effector 104. May be placed by positioning on a positioning element (eg, pin) on a portion of.

  In some embodiments, as best shown in FIG. 3, the teaching object 110 may be coupled to the base 126 of the nesting tool 128, which may be coupled to the tray 130 of the processing system 200. Good. The tray 130 may be removable from the frame 201 of the processing system 200. The approximate nominal position of the teaching object 110 is known, which is provided in a position and orientation in which the teaching object 110 is fixed relative to the nesting tool 128, and the base 126 of the nesting tool 128 is connected to the robot component 102. This is because it is provided at a nominally known position on the tray 130 provided on the frame 201 within the reachable range. For example, as shown in FIGS. 1A and 3, the base 126 may rest on one or more pads 130A (preferably three pads) formed on a tray 130 or on a nesting tool 128. Good. Two or more tray protrusions 130B (eg, tapered pins) extending from the tray 130 are similarly coupled with tapered holes, or holes and slots (shown in dotted lines in FIG. 1A) to allow the nesting tool 128 for the tray 130 to be A clear positioning can be further supported. Optionally, the pins may be formed on the nesting tool 128 and received in holes (or holes and slots) formed in the tray 130. Thus, although the nesting tool 128 is configured to be movable, it will be apparent that it can be precisely positioned at one or more desired locations within the reach of the robot component 102 and end effector 104. A plurality of sample racks (not shown) containing the specimen containers may be received on the tray 130 for processing.

  Another embodiment of a nesting tool 428 including a teaching object 410, an offset tool 414, and an offset object 418 installed on a common base 426 is shown in FIGS. As shown, the base 426 includes a generally L-shaped configuration that includes a first branch and a second branch disposed approximately perpendicular to each other, thereby providing the tray 130 described above. The pad 130A contacts the base 426 at three locations (indicated by dotted lines), thereby providing stability. Holes 431A and slots 431B (shown with only a slight extension) may be formed on the underside of base 426 and are adapted to receive and place pins 130B on tray 130 thereon. (See FIG. 3). A threaded portion (not shown) of the teaching object 410 can be received in a screw hole 433 provided in the base 426. The teaching object 410, the offset tool 414, the offset object 418, and the base 426 can each be manufactured from a suitable rigid material, such as stainless tool steel or the like. FIG. 4C illustrates the nesting tool 428 shown in cross section with the offset tool 414 and the offset object 418. As can be seen in the figure, the offset tool 414 may be placed on a compliant member 432 (eg, a coil spring), and the compliant member 432 can be pressed against the base 426 by a spring retainer 434. As shown in FIG. 4C, a portion 435 (eg, the central lower side) of the offset object 418 can be slightly recessed, so that it does not contact the recess 427. Accordingly, the frictional force for sliding the offset object 418 within the recess 427 of the base 426 can be minimized.

  5A-5C illustrate a taught subject assembly 500 that includes a taught subject 510 that can be installed in a bucket 206 of a centrifuge 205. Bucket 206 is pivotally mounted for pivotal movement on yoke 207. When a sample rack containing a specimen container (not shown) is received by the bucket 206 and the centrifuge 205 spins (rotates) to the operating speed, the bucket 206 is thrown outward by centrifugal force. Pivot about each mounting pivot axis 508 (shown for bucket mounting locations 2, 3 and 4). Once the robot offset has been correctly calibrated using the methods described herein, the teaching object 510 can be used to precisely position the bucket 206 relative to the end effector 104, whereby the bucket Transfer of the sample rack to 206 can be performed relatively accurately. The teaching object 510 can be detected by the position sensor 106 at another location within the reach of the robot component 102, for example at another bucket 206 (only one bucket is shown) or at another location.

A top view and bottom view of the taught assembly 500 are shown in FIGS. 5B and 5C, respectively. The teaching object assembly 500 may have a positioning base 514 having a teaching object 510 mounted thereon. Installation may be by suitable fastening means (eg screws). The positioning base 514 may include positioning points 515A-515C adapted to contact a precisely formed portion of the bucket 206 so that the positioning base 514 is precisely positioned at the bottom of the bucket 206 ( See FIG. 5D). Once positioned, the controller 108 (FIG. 1A) can move the robot component 102 to position the position sensor 106 at a nominal location of the teaching object 510. As shown in FIG. 5D, a routine is then executed to place the geometric feature 512 on the teaching object 510. The routine may be as follows.
-Start on bucket 206-Position sensor 106 (eg laser ranging sensor) moves down (in the far field of the sensor) until turned on at Z1
-Record Z1 readings-Move down 1 mm until the laser is off (close to the sensor)
-Moves in the + X direction until the position sensor 106 is turned on and finds the first vertical ends Xs, Ys-Moves 2 mm in -X (laser OFF) and + Y until the laser is turned on-With X1-2, Yc Find first horizontal edge-move to + Y-2Yc-Ys (laser OFF) and -X-Xs +
-Find the second Z at Z2-Move down 1 mm to turn off the laser-Move to + X until the laser turns on-Find the second vertical end X2, 2Yc-Ys-Xc = (X1 + X2) / 2 and Zc = (Z1 + Z2) / 2
-The target corner is found: Xc, Yc, Zc

  Using the above method, the exact location of the geometric feature 512 in X, Y, Z space can be found. Accordingly, the location of the geometric features of the bucket 206 can be accurately calculated. Using one or more additional teaching objects (eg, teaching object 110) on the teaching object assembly 500 or any other component of the processing system 200 within the reach of the position sensor 106, the precise placement of that component It will be appreciated that you may be able to help.

  An example method embodiment of the present invention will now be described with reference to FIGS. According to the method, as shown in FIG. 1A, the position sensor 106 is pulled down in the −Z direction to detect the position of the first surface 112A in the Z direction of the first geometric feature 112. When the laser ranging sensor is used as the position sensor 106, the laser ranging sensor outputs the signal line 106B when the distance between the position sensor 106 and the first surface 112A is equal to or less than a predetermined value (wide area value). A signal may be provided. Accordingly, when the laser ranging sensor is moved in the −Z direction toward approximately the center of the first surface 112A of the first geometric feature 112, the predetermined distance is the distance of the preset laser ranging sensor. When the end zone is reached, a signal is provided on line 106B. The memory stored in the control unit 108 can record the Z position coordinates when the signal on the signal line 106B is received there. The position sensor 106 is then moved further in the −Z direction until the laser ranging sensor is turned off (near the end of the laser preset area).

  Here, as shown in FIGS. 1B and 1D, the controller 108 is coupled with the robot component 102 until the first stepped end of the first geometric feature 112 on the first side is found. The position sensor 106 can be moved in the −X direction along the path 106X. Finding the first stepped edge occurs when the signal on signal line 106B reappears, which is the distance (d1) to second surface 112B, where beam 106A is on first surface 112A. This is because when it is projected off the edge and onto the second surface 112B of the teaching object 110 at the position of the stepped edge, it is again within the range of the laser ranging sensor. Similarly, the control unit 108 controls the robot component until a second stepped end is found on the other side of the first surface 112A of the first geometric feature 112, as shown in FIGS. 1C and 1D. 102 and the coupled position sensor 106 are moved in the + X direction along path 106X. Finding the second stepped edge is done when the signal reappears because the distance (d2) is within the preset range of the laser range sensor. The location reading of each of these stepped edges can be recorded in the memory of the control unit 108. The center position of the first geometric feature 112 in the X direction can be calculated by subtracting half of the difference between the readings of the first and second stepped edges X recorded in the memory of the control unit 108. . This may be repeated once again for higher accuracy once the first calculation is made.

  Place stepped edges of the first surface 112A along the path 106Y in the + Y and -Y directions, record the + Y and -Y coordinates in memory, and subtract half of the difference between the + Y and -Y coordinate measurements. Then, the same calculation in the Y direction may be performed by obtaining the center location of the teaching object 110 in the Y direction. These reading values may be recorded in the memory of the control unit 108. Once known, the calculation of Y may be measured again for improved accuracy. Therefore, in addition to the X and Y dimensions of the center line of the teaching object 110, the location in the Z direction of the first surface 112A can be correctly calculated.

  Referring now to FIG. 1E, the end effector 104 can be moved via commands from the controller 108, thereby moving the center line 104 C of the end effector 104 and placing it on the compliant member 132. The offset tool 114 is positioned roughly above the nominally known position. Then, the end effector 104 is pulled down until the ends of the fingers 104A and 104B come into contact with the upper surface (shelf) 114B of the offset tool 114. The end effector 104 is further lowered to slightly compress the compliant member 132 on which the offset tool 114 is placed and placed for access. Here, as shown in FIG. 1E, the gripper fingers 104A, 104B can be moved inward toward each other to grip the offset tool 114 by the pilot 114A. In this operation, the offset tool 114 is precisely positioned with respect to the center line 104C, and the tips of the fingers 104A, 104B of the end effector 104 are precisely positioned with respect to the first docking function 116.

  As shown in FIG. 1F, the offset tool 114 is now moved by the end effector 104 to a nominally known position of the offset object 118 via a command from the controller 108. The offset object 118 is approximately arranged and centered in the XY direction within a cylindrical recess 127 formed in the base 126 of the nesting tool 128. When docking is performed via moving the end effector 104 in the −Z direction, the interaction of the docking functions 116, 120 causes the slidable offset object 118 to move along the plane of the recess 127 X and / or Slide and shift in the Y direction and reposition to a new location in the recess 127. The offset tool 114 can then be carefully removed along the + Z direction so as not to interfere with the location of the offset object 118 and can return to a stationary position on the compliant member 132 (see FIG. 1E).

  Next, as shown in FIG. 1G, the robot component 102 moves the position sensor 106 to a nominal position of the offset target 118 in the XY space by the control unit 108. Similar to the teaching object 110, the Z position in the Z direction of the upper surface (first offset surface) 122A can be calculated by lowering the position sensor 106 until reaching the farthest end of the range of the laser range sensor. This Z reading value can be recorded in a memory in the control unit 108. The routine then searches each stepped edge in the X and Y directions of the second geometric feature 122 in the same manner as described above for the first geometric feature 112 of the teaching object 110. The only difference is that the second docking feature 120 is included on top of the second geometric feature 122, so for the first offset surface 122A, the search is centered on the second geometric feature 122. It must start at a position offset from. From this, the X and Y center coordinates of the offset object 118 can be easily calculated based on the respective differences between the + X and −X readings and the + Y and −Y readings. These X and Y center values may be stored in a memory.

  One or more coordinate directions (from one of these X, Y, and Z values calculated based on the reading acquired and stored for the teaching object 110 and the reading acquired and stored for the offset object 118 ( The exact position offset of X, Y, and / or Z) can be calculated. In particular, a position offset between the end effector centerline 104C and the beam 106A of the position sensor 106 in the X and Y directions may be calculated. Similarly, a position offset between the tips of the fingers 104A, 104B and the Z preset area measured by the position sensor 106 can be calculated. As such, the internal positioning of the robot component 102 can be zeroed at (0, 0, 0) to reflect the offset so that the positioning of the end effector 104 is within the reach of the robot component 102. To be appropriate.

  Referring back to FIG. 3, the nesting tool 128 can be positioned at any desired position on the tray 130 to obtain offset position information. For example, the nesting tool 128 is shown positioned at the furthest distance from the zero position of the robotic device on the tray 130. Once the offset information is obtained, the same nesting tool 128 can be relocated to another location on the tray 130 or on another system component where it is desirable to obtain position information. And it should be understood that in some embodiments, multiple nesting tools may be used in a system for calculating location information regarding the exact location of other system components. For example, FIG. 6 illustrates the placement of multiple nesting tools 128 on various locations on the tray 130.

  As shown in FIG. 6, additional nesting tools 128A may be placed in the inflow / outflow region 640, where cassettes and / or specimen containers, vials, test tubes, etc. may be pedestaled. Optionally, the inflow / outflow region 640 may simply be a storage location for the nesting tool 128A accessed by the end effector 104. For example, the end effector fingers 104A, 104B grasp the post of the teaching object 110 and move one or more nesting tools 128A to any location within the processing system 200 within the reach of the robot component 102. Also good. Additional teaching objects 610 may be provided for various other system components where position in X, Y, and / or Z space is desired. For example, the teaching object 610 may be provided in the feeder 615. The feeder 615 may be a tool feeder having a rotatable magazine, where various tools may be accessed by the end effector 104 as needed. Optionally, the feeder 615 can function to supply a specimen within the processing system. A teaching object 610 having a configuration different from that of the teaching object 110 of the nesting tool 128 may be used. For example, the teaching object 610B may be used to calibrate the location of the bucket 206 installed on the yoke 207 of the centrifuge device 205 as previously described (only the yoke 207, the bucket 206, and the teaching object 610B). Shown). The teaching object 610B is shown raised above the bucket 206, but is received at the bottom of the bucket 206 during location calibration.

  The operation of the method of providing an offset between the end effector 104 and the position sensor 106 of the robot offset calibration system 100 of the present invention will now be described in more detail with reference to FIG. The method 700 provides, at 702, a robot component having an end effector and a position sensor coupled thereto, and at 704, provides a teaching object (eg, 110) in a work area reachable by the end effector (eg, 104). The teaching object has a first geometric feature (eg 112). The method 700 includes providing an offset object (eg, 118) reachable by the end effector at 706, wherein the offset object includes a second geometric feature (eg, 122), and at 708, an offset tool. (E.g., 114) and at 710, sensing a first geometric feature to be taught by a position sensor (e.g., 106). The method 700 includes engaging the offset tool (eg, 114) with the end effector (eg, 104) at 712, moving the offset tool (eg, 114) to the offset object (eg, 118), at 714, and at 716. And docking the offset tool (eg 114) with the offset object (eg 118). The method 700 then records the tool coordinates at 718 after docking the offset tool (eg, 118) and at 720, the second geometric feature of the offset object (eg, 118) by the position sensor (eg, 106). (For example, 122) can be detected.

  While the invention is susceptible to various modifications and alternative forms, certain system and apparatus embodiments and methods are illustrated by way of example in the drawings and are herein described in detail. However, it is not intended to limit the invention to the particular systems, devices, or methods disclosed, but rather covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. It should be understood that

Claims (13)

A robot component having an end effector and a position sensor coupled thereto;
A teaching object having a first geometric feature;
An offset tool including a first docking function adapted to be engaged by an end effector;
An offset object having a second docking function adapted to be engaged by the first docking function and a second geometric feature adapted to be detected by the position sensor;
Including a robot offset calibration system. Teaching the subject, the offset tool, and each of the offset target, is mounted on a common base, the robot offset calibration system of claim 1. The offset tool is placed on the compliant member, the robot offset calibration system of claim 1, wherein. The offset tool includes an adapted pilot to be grasped by the fingers of the end effector gripper, the robot offset calibration system of claim 1, wherein. Offset subject is slidable on the surface, the robot offset calibration system of claim 1, wherein. 6. The robot offset calibration system of claim 5 , wherein the offset object is slidable on a common base surface of the nesting tool. Second geometric characteristics of the offset target includes first and second surfaces, the first surface, from that of the second surface are located at different heights, the robot offset of claim 1, wherein Calibration system. First docking function of the offset tool includes a conical surface, the robot offset calibration system of claim 1. The second docking function of the offset target comprises a curved surface, the robot offset calibration system of claim 1, wherein. Second geometric characteristics of the offset target comprises two or more stepped end face, claim 1 robotic offset calibration system according. First geometric feature of teaching object comprises at least two stepped end face, claim 1 robotic offset calibration system according. Base and
A teaching object having a first geometric feature mounted on a base and adapted to be detected by a position sensor;
An offset tool installed on the base and having a first docking function;
A second docking function mounted on the base and adapted to be engaged by the first docking function of the offset tool; and a second geometric feature adapted to be detected by the position sensor; An offset object having
A calibration aid including: A tray,
A nesting tool coupled to a tray,
Base and
A teaching object having a first geometric feature mounted on a base and adapted to be detected by a position sensor;
An offset tool installed on the base and having a first docking function;
A second docking function mounted on the base and adapted to be engaged by the first docking function of the offset tool; and a second geometric feature adapted to be detected by the position sensor; An offset object having
Including nesting tools,
A calibration aid assembly comprising:

Images